cifs: add smb2 POSIX info level
* add new info level and structs for SMB2 posix extension
* add functions to parse and validate it
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index ab31d6f..08d6a13 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -4302,6 +4302,101 @@ SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,
return rc;
}
+static int posix_info_sid_size(const void *beg, const void *end)
+{
+ size_t subauth;
+ int total;
+
+ if (beg + 1 > end)
+ return -1;
+
+ subauth = *(u8 *)(beg+1);
+ if (subauth < 1 || subauth > 15)
+ return -1;
+
+ total = 1 + 1 + 6 + 4*subauth;
+ if (beg + total > end)
+ return -1;
+
+ return total;
+}
+
+int posix_info_parse(const void *beg, const void *end,
+ struct smb2_posix_info_parsed *out)
+
+{
+ int total_len = 0;
+ int sid_len;
+ int name_len;
+ const void *owner_sid;
+ const void *group_sid;
+ const void *name;
+
+ /* if no end bound given, assume payload to be correct */
+ if (!end) {
+ const struct smb2_posix_info *p = beg;
+
+ end = beg + le32_to_cpu(p->NextEntryOffset);
+ /* last element will have a 0 offset, pick a sensible bound */
+ if (end == beg)
+ end += 0xFFFF;
+ }
+
+ /* check base buf */
+ if (beg + sizeof(struct smb2_posix_info) > end)
+ return -1;
+ total_len = sizeof(struct smb2_posix_info);
+
+ /* check owner sid */
+ owner_sid = beg + total_len;
+ sid_len = posix_info_sid_size(owner_sid, end);
+ if (sid_len < 0)
+ return -1;
+ total_len += sid_len;
+
+ /* check group sid */
+ group_sid = beg + total_len;
+ sid_len = posix_info_sid_size(group_sid, end);
+ if (sid_len < 0)
+ return -1;
+ total_len += sid_len;
+
+ /* check name len */
+ if (beg + total_len + 4 > end)
+ return -1;
+ name_len = le32_to_cpu(*(__le32 *)(beg + total_len));
+ if (name_len < 1 || name_len > 0xFFFF)
+ return -1;
+ total_len += 4;
+
+ /* check name */
+ name = beg + total_len;
+ if (name + name_len > end)
+ return -1;
+ total_len += name_len;
+
+ if (out) {
+ out->base = beg;
+ out->size = total_len;
+ out->name_len = name_len;
+ out->name = name;
+ memcpy(&out->owner, owner_sid,
+ posix_info_sid_size(owner_sid, end));
+ memcpy(&out->group, group_sid,
+ posix_info_sid_size(group_sid, end));
+ }
+ return total_len;
+}
+
+static int posix_info_extra_size(const void *beg, const void *end)
+{
+ int len = posix_info_parse(beg, end, NULL);
+
+ if (len < 0)
+ return -1;
+ return len - sizeof(struct smb2_posix_info);
+}
+
static unsigned int
num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
{